A quick look at Seagate's 1.5TB Barracuda firmware update
 

Seagate broke the terabyte barrier with a 1.5TB version of its Barracuda 7200.11, but soon after its release, users of the drive started experiencing random freezing. A firmware update has since corrected the issue, and we've taken it for a quick spin to see if there's a performance hit.

http://techreport.com/articles.x/16221